Description: Looking to the south from my front porch we were noticing the thunderstorms around us. Then in the distance, about 20 ft above the rooftops across the street, at the ten o'clock position a green ball of light appeared. It looked basketball sized and the green light was enhanced by clouds and moisture in the air. It travelled from the ten o'clock position horizontally to the two o'clock position in a straight line and then the light went off or disappeared. The most unusual part of this is the rate of speed it traveled. Amazing fast less that a second. And the distance covered was what appeared to be about 2 to 3 miles. Also, there were no noises associated with the movement of the light.